As X-ray said you really need some level of redundancy when dealing with multiple drives in a pool unless you:
a) are feeling lucky punk.
b) only have data which can be safely lost if you had a problem
or
c) keep good backups elsewhere
You don't need a raid controller that does JBOD though. You can use logical volumes on linux with
LVM or
ZFS on Solaris/OpenSolaris with any device that the OS can see using disks attached to any controller (e.g. some on IDE some on SATA and some on USB)
ZFS is very easy to use and get to grips with and offers many cool features (Filesystem compression, incremental snapshots, 256bit checksums on data).There are a few downsides, such as ZFS doesn't allow you to remove disks from a pool (yet). You can grow it using odd sized disks in any arrangement though. OpenSolaris works best on fairly modern hardware though and can need lots of RAM (>1GB) to get the best performance. Learning OpenSolaris is quite trivial and there is not too much of a learning curve. OpenSolaris doesn't support as much hardware as Linux either. You can get ZFS on linux but it's still has some issues.
I'd stick with LVM if I were you simply on the basis that you might possibly need to reduce the size of your data pool.
Kev
